I just bought a massive old Cincinnati (I think) pedestal grinder that I was told was 440 only. Upon inspection it appears to have 7 leads at the junction box. I was expecting 9 leads if it were a dual voltage motor. Am I just not seeing 2 of them or is 7 leads enough. I must confess that I have not pulled all of the leads out of the box for fear of damaging them. They appear to be in fine shape, but I only want to move them around once if possible. There is no diagram in the junction box/switch bolted to the motor. What do I need to rewire this beast to 220 volts?
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440 to 220
- Thread starter Avanti
- Start date
- Replies 3
- Views 1,214
peterh5322
Diamond
- Joined
- Dec 15, 2002
- Location
- Monterey Bay, California
Seven leads is a single-voltage two-speed "consequent pole" ∆/YY winding with open ∆ option (opening the ∆ accounts for the seventh lead), but this configuration is normally accompanied by three additional leads for a third speed single-voltage Y winding, which would mean ten total leads, or seven additional leads for a third and fourth speed single-voltage ∆/YY winding, also with open ∆ option, which would mean fourteen total leads.
I poked around in the box and there are 9 leads, not 7. The ohm meter says it is a Y wound 2 voltage motor. I guess I really scored on this one. I will probably fire it up tomorrow from a long distance away. It has new wheels on it but I expect that 18" wheels @ 1200 RPM would make for quite an explosion if one of them is cracked. I plan to let it run for 30 minutes or so before I move it inside.
